Lifting-jack.



No. 745,180. v PATENTED NOV. 24, 1903. T. HAMPTON. LIFTING JACK.

APPLICATION FILED AUG. 18, 1903.

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Inn/6M7;- jzomaad amffa7a No. 745,180. PATENTED NOV.'24, 1903..

. T. HAMPTON.

LIFTING JACK.

APPLICATION FILED AUG. 18, 190 3.

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UNITED STATES Fatented November 24, 1903.

PATENT OFFICE.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. }45,180, dated November 24, 1903.

Application filed August 18, 1903. Serial No. 169,891. (No model.)

' and arrangement or combination of parts hereinafter described constituting an improved lifting-jack especially useful for the raising of motor road-vehicles and other light road-vehicles but the said improved liftingjack may be used for lifting purposes generally.

In order that my invention may be the better understood, I remark that in lifting-jacks as ordinarily constructed it invariably happens that in use the head of the jack has to be raised by the operating mechanism of the jack before the head is brought into contact with the body or load to be raised, and in consequence thereof the range of lifting motion which the jack is capable of effecting with the load is more or less reduced.

My invention has for its object so to construct and arrange the parts of lifting-jacks that the head may be brought into contact with the body or load to be raised directly by handthat is, without operating the lifting mechanism proper and for this purpose I make the lifting-barthat is, the bar which is raised by the operating mechanism of the jack-hollow or tubular, the axial hole in the said bar being angular (preferably rectangular) in'cross-section. In the said axial hole of the lifting-bar a supplementary lifting-bar with rack-teeth on two of its opposite sides is arranged and the top of the lifting-bar proper is provided with two horizontal spring sliding bolts or the like, the said bolts terminating at their outer ends in externally-projecting knobs. The top of the supplementary lifting-bar carries the head of the jack, which is loose-that is, is capable of rotary motion, as is usual. The inclined sides of the rackteeth or the bevel-faces of the bolts are so arranged that the supplementary lifting-bar may be lifted directly by hand toits full extent or to an intermediate height in the lifting-bar proper, but not removed therefrom, and will be retained by the spring sliding bolts or other retaining mechanism in the position' to which it has been lifted. Thus it will be understood-that by the use of the supplementary lifting-bar the user of the jack has the power virtually of extending the length of the lifting-bar proper, so as to bring the head of the jack into contact with the load or body to be raised before bringing into Work the operating mechanism of lhe jack. Consequently the body or load can be raised to the full height of the lifting range of the jack. After the body or load has been lowered to the ground the'supplementaryliftingbar may be permitted to fall by its own weight into the lifting-bar proper by pulling outward the spring sliding bolts, hereinbefore described.

Figure 1 of the accompanying drawings represents in front elevation, Fig. 2 in side elevation, and Fig. 3 in plan, the latter partly in horizontal section, a lifting-jack provided with the improvements constituting the said invention, the parts of the jack being in their normal or closed positions. Fig. lrepresents the jack in side elevation with the supplementary lifting-bar partially raised by hand; and Fig. 5 is a vertical section of a portion of the jack, the said section being taken on the line m m, Fig. 3, showing how the supplementary liftingbar is retained in its raised position. Fig. 6 is a vertical section of the jack after the partial raising of the lifting-bar proper by the operating mechanism of the jack, the said section being taken on the line y y, Fig. 3.

The same letters of reference indicate the same parts in the several figures of the drawings.

a is the hollow or frame-like standard of the jack provided at its lower end with the base or foot a a the liftingbar I) (also hollow) is situated and works the said hollow lifting-bar b, having on one of its outer sides a rack the teeth of which are portions of a hollow worm or screw.

To the hollow standard a a combined worm and worm-wheel or pinion c c and a worm d (hereinafter called the primary worm) are fitted. The axis of the primary Worm d has a square hole 01 for the reception'of the key of the jack.

In the said hollow standard 7 The primary worm d, combined worm and worm-pinion c 0 and lifting-bar b are so arranged that on the operation of the jack the primary worm d gears with and rotates the worm-pinion c and with it the worm c,and the latter gears with the rack of the lifting-barb and effects the raising and lowering of the said lifting-bar in the hollow standard a.

In the hollow lifting-bar b the supplementary lifting-bar e is fitted, the said supplementarylifting-bar having in opposite sides rackteeth, as is best seen in Fig. 5. The head of the liftingbar b is provided at opposite sides with bevelended spring-bolts f f,which by the action of the springs g 9 (see Fig. 3) are normall-y preserved in engagement with the teeth of the racked bar 6, but which bolts are capable of being drawn outward by hand when after use it is desired that the supplementary lifting'bar 6 shall take its lowermost position in the lifting-bar Z). The complete withdrawal of the supplementary lifting-bar is prevented by a stop-pin '6 (see Fig. 6) on the said supplementary lifting-bar e.

The supplementary lifting-bar e is provided with a loose head h-that is, a head capable of a turning or rotary motion on the supplementary lifting-bar e.

The lifting-jack described is used as follows: After the jack has been placed in the required position under the body of the vehicle or other body to be raised the supplementary lifting-bar e is lifted by hand until the loose head h of the same is in contact with the said vehicle or body to be raised. The lifting-bar l) is then raised by rotating a winch or key (not shown) fitted into the hole (Z of the worm (Z, by which action the primary worm (Z and combined worm and worm-wheel c c are rotated. The lowering of the load is effected by reversing the rotation of the winch or key, and after the vehicle or body has reached the ground or its support the supplementary lifting-bar e is allowed to descend by drawing outward (by hand) the two spring-bolts ff, and thereby disengaging them from the racks of the supplementary liftingbar.

The supplementary lifting-bar described may be used with or applied to lifting-jacks of various constructions.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In alifting-jack, a base, a hollow liftingbar, means for raising and lowering said lifting-bar, a plurality of horizontally-movable spring-pressed bolts,having beveled ends, carried by said lifting-bar, and a supplementary lifting-bar movable vertically in the hollow portion of said hollow lifting-bar, said supplementary lifting-bar having a plurality of sets of rack-teeth, each of which sets is engaged by one of said spring-pressed bolts.

2. In a lifting-jack, a base, a primary wormshai't on said base, a combined worm and pinion on said base, the pinion portion of which is in mesh with said primary worm-shaft, a hollow lifting-bar, in said base, having a segmental worm in mesh with the worm portion of said combined worm and pinion, a pair of horizontally movable spring pressed bolts carried by said hollow lifting-bar, each of said bolts being beveled at its inner end and having a knob on its outer end, and a supplementary lifting-bar movable vertically in the hollow portion of said hollow lifting-bar, said supplementary lifting-bar having two sets of rack-teeth, each of which sets isengaged by one of said spring-pressed bolts.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

THOMAS HAMPTON.

lVitnesses:

RICHARD SKERRETT, ARTHUR JOHN PowELL. 

